Electrode for electrolytic cells



Jan. 27, 1931. K. ROTH ELECTRODE FOR ELECTROLYTIC CELLS 2 Shegts-Sheet 1INVENTOR Karl R025 0. TTORNEYS Original File d Jan. 21, 1926 Jan. 27,1931. K. ROTH ELECTRODE FORELECTROLYTIC CELLS 1926 2 Sheets-Sheet 2Original Filed Jan. 21

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6 I I 7 91/1 7/4 I IIIIIIIII l I w I M I IIIIIIIIIII I z 2 5 4 5 a F 4INVENTOR, Karl R0171 TTORNEYS Patented Jan. 27, 1931- UNITED STATESPATENT? OFFICE.

KARL ROTH, or LUDWIGSHAFEN-ON-THE-RHI1\TE, GERMANY, AssIGNoR 'ro I. e.FAB;

immunesrRmmKrIENeEsELLscHArr, or FRANKFORT-ON-THE-MAIN, GERMANY,

A con'ronerron or GERMANY ELECTRODE FOR ELECTROL Y'JJIG CELLS Originalapplication filed January 21, 1926, Serial No. 82,761, and in GermanyJanuary 22, 1925. Divided and this application filed February 7, 1928,Serial No. 252,586. Renewed July 15, 1930.

The present inventionrelates to electrodes for the electrolyticdevelopment of gases, especially by the decomposition of water Thesubject-matter of this application has been divided out from mycopend-ing applicat on Ser. No. 82,761, filed Jan. 21, 1926. My improvedelectrodes have the advantage that the formation of foam from theelectrolyte and the fine gas bubbles formedvis avoided to a great extentand units of high capacity can be constructed on a comparatively smallfloor area. My invention Will be explained with reference to theaccompanying drawings which,

however, are diagrammatical and to which I do not wish to limit myinvention.

Fig. 1 shows a vertical section of one'form of my improved electrode.Fig. 2 shows a front perspective View thereof partly broken away. Fig. 3shows a vertical section of a modified form of my electrode. Fig. 4 is afront perspective .view of same. Figs. 5, 6 and 7 are vertical sectionalviews of some other modifications of my electrode.

The electrode according to my invention consists of a number of pocketsan arranged one upon another in one or several series. The front-wall (bin Figure '1) of the pockets fronting the counter-electrode or thediaphragm between the two electrodes is made from metal provided withsuitable openings to allow the passage of gas as for example borings orslits, or it may be made from Wireme sh. If both sides of the-electrodeare to be used for electrolysis, either as a doublesideunipolar or asbipolar electrode, both the frontand back-walls of the pockets must bemade of metal and permeable for the gases. If only one side is used forelectrolysis the pockets arepreferably also made wholly of metal thoughthis is not necessary.

The bulk of the gas is developed in the form of fine bubbles at theouter surface of the electrode, part of which directly passes throughthe openings of the electrode wall to-the interior of the pocket. Therest of the gas bubbles is forced into the interior by suitable guidingdevices, for example by horizontal partitions it between the electrode:and the diaphragm z (see Figure 6) which at electrolyte.

the same time may serve as supports for the diaphragm. The partitionsmay be made of any material resistant to the action of the The distancebetween the said partitions and the upper edges of the' pockets may varyin accordance with the construction of the walls of the pockets.

The gases collected in each pocket are led ofi" through the upper wallof the pocket in any suitable manner, for example by pipes or channels,and are generally introduced into the next higher pocket. The said pipesor channels leading the gases off may have any desired cross-section,and preferably their lower end extends a little into the upper part ofthe lower pocket, the walls of which are correspondingly left,impermeable to gases in their upper part; By this construction, the finegas bubbles rising within the pockets are forced to collect near the topof them to form a kind of gas cushion. As soon as additional gas causessaid gas cushion toexceed the extension of the pipes or channels intothe pocket, gas is discharged in the form' of big bubbles through allupper pockets: Thereby the formation of a very fine emulsion of theelectrolyte with the fine gas bubbles is'prevented which not only wouldgive rise to a foam, but would be liable to run backto the outside ofthe pocketand on account of its reduced conductivity would increase theresistance of the cell. As the quantity of gas increases from below toabove, it may be advantageous to increase the number or the crossse'ction of the gas leading pipes or channels in the upper pockets. Insome cases it appears c-onvenientnot-to pass the big gas bubblessuccessively through all of the upper pockets, but directly intotheuppermost one or tothe collecting pipe whether by means of pipes runningoutside saidpockets' in the spaces between the pockets or through thesaid spaces themselves, or for example'by prolonged pipes or channelsdirectly running through several of thesepockets as indicated in Figure7. i e

- When gas is discharged from the cushion in a pocket, the bubbles dragalong considerable quantities of the electrolyte contained in thatpocket. The resulting vacuum causes be made of one piece with the 5suitable pipes or channels 7 and g which must not necessarily connectvertically ad- .xjacent pockets. It may be desirable to connect moreremote pockets by means of such 'pes and g which may be led between orbin or through adjacent pockets (seem .in Figure 7 a a By a suitablearran ement and size of the pipes or channels o y small quantities ofthe'emulsion formed of fine gas bubbles and electrolyte are allowed topass to upper or lower pockets, and moreover a continuous circulation ofthe electrolyte in all pockets and thereby a uniform concentration ofthe electrolyte is produced.

-The. exchange of concentration between anolyt'e and catholytemay beassisted by arranging the anode pockets and cathode pockets fronting onediaphragm in a vertically staggered relation to .each other.

The uppermost pockets may be, built as chief gas collecting chambers(see Figures 2 and 4). For this purpose, the upper arts of their sidewalls must be impermeable to for nearly any desired capacity byassembling the required number of pockets in ver-' tical and horizontaldirection without encountering the difiiculties that would be causedwith other cells by enlarging their size.

The electrodes may be constructed in many different ways. -Instead ofusing one layer of pockets, there may be two layers w1th their'backsides against each other (see Fi es 3 and 4) so as to obtain adouble-side v. electrode (Figures 4' and 7) which may be used as aunipolar or as a bipolar electrode. In the latter case, care must betaken that the electrode alsosecures aseparation of the electrolytes andgases of the two adjacent compartments which may be efiected by suitabletightenings k (Figure 7) between the pockets.'

The pockets of one electrode can be made, all or in groups, of one or afew single ieces of a metal, for example of a casting. The front walls,of perforated sheet-metal or of wire-mesh or the like are put on thesaid pockets afterwards and connected there-' to metal to metal tosecure good electric conductivity. By this manner of producing 1 theelectrode of one or a few single pieces to of metal the metallic contactof the front walls with the source of current isv easily efiected. Y v

the case of bipolar electrodes the tightening walls between thefpocketsmay name. Douconsisting of a a number of poo ets by horizontal andvergas. I

The hereinbefore described electrode has the advantage that it may bebuilt as a unit ble side-unipolar electrodes (Figures 5 and ,6) may bemade of one layer of.pockets with perforated frontand back-walls so asto allow the gases to enter into the pockets.

Or, all pockets may be surrounded by a wall common to all which means anelectrode reat chamber divided into tical walls. The horizontal wallsare provided with pipes or channels, as described above, so as to formgas collecting rooms, and mayalso be provided with pipes for circulatingthe electrolyte exactly as when using separate pockets. Figure 6' showsone form .of such electrodes.

Automatic devices may be arranged for a supply of water to replace thatconsumed during the electrolysis so as to maintain a certain quantity ofelectrolyte in each cell. In order to enable a cooling which whenworking at great outputs may become necessa'ry, suitable hollow spacesare provided in or between some of the pockets apart from the roomcontaining the electrolyte and filled with a cooling liquid.

I do not claim in this claimed in the aforesaid original applicationSer. No. 82,761. 7

What I claim 1. A double side unipolar electrodefor application my -newor improved electrode generically nor bipolar electrodes specifically,such being the development of gases, which consists-in l a structurecomprising a number of pockets arranged one u on another and havingpermeable metal rontand back-walls and connection pipes between thepockets for pocket.

leading the gases upwards which pipes exv tend a little into the upperpart 0 alower 2. A double-side unipolar electrode for the development ofgases, which consists in a structure comprising a number of pocketsper-= e arranged one upon another and ha meable metal frontandback-walls an connection pipes between the pockets for leading the gasesupwards which pipes extend a little into the upper part of a lowerpocket, and separate pipes for circulating the electrol 3. A dou le-sideunipolar electrode for the development of gases, which consists in astructure comprising a number of pockets arranged one upon another andhaving permeable metal frontand back-walls and connection pipes betweenthe pockets for leading the gases upwards which pi s extend a little mtothe upper part o a lower pocket, and separate pipes for circulating theelectrolyte, 'the upper edge of the front and back-walls of each pocketbeing provided with a guiding device forcing gas bubbles into theinterior of the pocket.

4. A. double-side unipolar. electrode for the development of gases,which consists in a structure comprising a number of pockets arrangedone upon another and havin permeable metal frontand back-walls anconnection pipes between the pockets for leadin the ases upwards whlchpi extend a 'ttle into the upper part a lower pocket, and separate pipesfor circulating my hand.

the electrolyte the upper art of the front: wall of the highest 00 et ofa vertical series being impermea le to gas.

5. A double-side unipolar electrode for the development of gases, whichconsists in a structure comprisin a frame divided by partitions into anum er of pockets having permeable metal frontand back-walls andconnection pipes between the pockets for leading the gases upwards whichpipes extend a little into the upper part of a lower pocket.

In testimony whereof I have hereunto set' KARL ROTH.

